An object of the invention is to provide a stroke simulator and a bush for a stroke simulator configured so that a bush provided to a stroke simulator can be attached without direction management. The stroke simulator generates brake reaction force by a simulator piston that is displaced within a cylinder by hydraulic pressure generated according to the operation of a brake pedal by a driver. A cylindrical rubber bush (226) which is elastically deformed in an axial direction by pressure from the simulator piston to generate brake reaction force, the bush characterized in that a first end section (226c1) on the simulator piston side and a second end section (226c2) facing the first end section (226c1) contain the same number, at least two, of concave sections (226d) which are concaved in the axial direction, and the concave section (226d) formed in the first end section (226c1) and the concave section (226d) formed in the second end section (226c2) are formed in different positions in the axial direction.